my nephew has an 02 superduty with a 5.4 engine, 100k miles. last month it started a cold valve tap. now it does it almost all the time. is this something to worry about, and is it an easy fix, or just let it be as it is not anything to worry about??

 

You sure it isn't broken exhaust manifold studs causing a ticking exhaust leak?
I would also check the spark plugs asap to make sure they are tight. If one is loose, it will soon blow out and take the threads in the head with it.

 

nope on the exhaust leak, it is a definite valve tap. and it was doing it before i changed the spark plugs, which i tightened to the specified 11 ft lbs of torque.

 

HMM, this isn't very common in these engines. I thinking that you may have a bad lash adjuster letting the cam follower have too much play.

 

is this something to worry about, or is it a turn the radio volume up kind of thing.

 

As long as the oil pressure is good, I wouldn't worry too much.

 

Any chance it's an injector ticking? Much more common than a valve and easier to fix too...

 

no idea. it is on the passenger side, #3 or 4 cylinder. very loud on cold start, and then quiets down after it warms up. up until 2 weeks ago, it would go away after oil pressure built up.
i have no idea what an injector tick sounds like, but this sounds exactly like my 289 does when the lifter collapses after sitting for a few weeks.

 

Sounds like a bad lash adjuster to me.

 

tcj

Be careful with this... Check your spark plugs, I had the same type of sound, thought it was an exhaust leak... and let it go for 2 weeks... Just blew the #4 spark plug out of the head. The #4 is hard to get to but check it make sure it's tight. After it happened to me the #3 and #4 are common blowouts... and it rips the threads out... needless to say I'll be removing my heads over the weekend...

 

I had a similar loud valve tap noise problem with my 02 SuperCrew 5.4 engine when it was cold. I switched oil brand to Amsoil XL two years ago and it cured the problem. I will recomend you to experiment with another brand of oil and maybe this will fix the problem.

 

My 97 made a noise I thought was a lifter or valve but I was told it was piston slap and it went away as it warmed up like you describe. If its the same thing you have its just the short skirt pistons expanding as they heat up and that it was normal for these. NO idea if this is the same or helps, just what I experienced.

 

Old school trick;
Use a dowel or broomstick to your ear and to the cylinder head, inside and out. Try the block, injectors and the valve cover too. This might help localize it further than you already have.
This is partly how I diagnosed a broken piston skirt years ago on a SBC.
My '02 SD sounds horrible at a cold start (below freezing) for almost a minute, like what you describe but goes away.

 

sounds like a bad lifter. find out what cylinder it is and take the valve cover off. check the lifters. i would not let it go.

 

if it ever stops raining, he is going to bring it over for a closer look. i want to look at the front end also. the last time i saw it it looked like the camber was out on the driver side.